VU Physics and Astronomy Colloquium

Friday, January 30, at 3:20 PM in NSC 224. Join us for refreshments in NSC 231 at 3:05 PM.

"Interstellar Abundances in the Magellanic Clouds"


Dr. Dan Welty, Dept. of Astronomy, University of Illinois at Urbana/Champaign

Studies of the interstellar gas and dust in the Large and Small Magellanic
Clouds explore somewhat different environmental conditions from those
typically probed in our own Galactic interstellar medium -- lower overall
metallicities and dust-to-gas ratios, generally stronger ambient radiation
fields, and significant differences in UV extinction.  We will discuss
high-resolution UV and optical spectra of interstellar absorption lines
toward stars in the Magellanic Clouds -- which have provided both accurate
gas-phase abundances and evidence for differences in dust composition
and/or overall metallicities in some sight lines.  Knowledge of the
interstellar abundances in the Magellanic Clouds should aid in
understanding the absorption-line systems seen toward distant quasars and
gamma-ray bursts (which exhibit some similar properties) -- and thus aid
in tracing the build-up of heavy elements and dust in galaxies over the
history of the Universe.